London Victoria station- 2 hours free time before theatre show with teenagers, any good suggestions on how to spend the time?

[QueenCoconut]

We are visiting London this Saturday, arriving at Victoria station around midday. We have booked a nice cafe for lunch and then we have 2 hours to kill before a theatre show. It’s my DD birthday trip, her and her two friends are coming and we would like to let them go shopping and exploring on their own before the show. They are 17.
They love books, art, design and are also into comics, anime, manga. They don’t enjoy clothes/ make up shopping and they’ll already have eaten by that time so I‘m excluding these options. Are there any good interesting shopping areas, markets that they would enjoy? Perhaps any specialist shops or a nice interesting museum? Any suggestions would be gratefully received.

That’s the show we are going to see.
They have chosen to go to Forbidden Planet but I think we will have to go with them, take the tube and ensure we get back on time do the theatre. Probably an hour max in FP.
lots of great suggestions here thank you!

Waterstones at Piccadilly? My book loving teen can spend an age in there it's got so many floors.